Increasing levels It's been a point of difference among scientists for at least 20 years - is Antarctic ice growing or shrinking?

Now for the first time, an international team of scientists has delivered the most accurate assessment yet of both poles.

Using observations from 10 different satellite missions, researchers have confirmed that Greenland and Antarctica are both losing up to three times as much ice as they were in the 1990s.

According to the study, published today in the journal Science, melting ice from polar glaciers has contributed around 11 millimetres to global sea level since 1992.

Study co-author, Andrew Shepherd from the University of Leeds says this latest finding is two or three times more reliable than previous estimates.

"At the last IPCC assessment report, the uncertainty, particularly in Antarctica, was quite large," says Shepherd. "In fact it wasn't even clear whether Antarctica was growing or shrinking, which is a pretty fundamental issue."

"Now that we're able to improve the accuracy of the estimates, we can say for sure that Antarctica is losing ice as well as Greenland."

According to Shepherd, Greenland is losing three times as much ice as Antarctica, and that the rate of ice loss in both regions is increasing.

"We see now that the ice sheets are losing three times as much ice today as they were 20 years ago. So it's on the increase."

Recent surveys of Antarctic sea ice have shown a gradual increase in area, but Shepherd says this is countered by the decreases in land ice mass.

"It's true that the sea ice cover in Antarctica has been increasing but in west Antarctica we don't see that picture really at all," he says.

"We just see a progressive acceleration of glaciers which is causing more and more ice loss. And we think that that picture is consistent with oceanic warming in that area of Antarctica."